Pwnage does not advance past unpacking

When I try to use pwnage to create a firmware file it stops at the unpacking part. At one point I let it go for six hours and it still did not get past the unpacking.
I am using a ppc apple, which could be the problem but I have not seen anything saying that it does not work.
I was able to jailbreak my iPod touch 2g using a custom ipsw but now that there is the patch to boot by sending run rs I would like to be able to make a custom firmware.